I had to do this for Kiddo #1 when her passport was about to be surrendered for a visa application and we had travel planned to Canada that would require a passport. The opportunity to study abroad that summer and need for a visa application arose with short notice, so the situation was unavoidable.
Honestly, it was a stressful situation. I contacted a couple companies that will take care of everything for you, and they gave me different lists of what I had to provide. I found it disconcerting that they weren’t in agreement on how to handle the situation and so I decided to handle it myself.
The travel and surrendering of the passport were going to occur around the same time, so we still had the passport with us when I made the appointment at the passport processing center. (Which had to be within a short time frame of our intended travel, which only added to the stress.) We got up at 4am, and Kiddo and I drove 5.5 hours there with every. single. document. we could possibly imagine ever needing in our posession. I also had printed out two different passport application forms (which had been the big disagreement between the two expeditors).
We had to show proof of need - international travel and visa application - before they’d even let us in the office. Then we went to the first window and were asked to show Form A and all supporting documents. Person #2 took a look and then smugly told us that was incorrect; we needed to show Form B and all supporting documents. The look of surprise on her face when I pulled out Form B and all supporting documents made my day. They actually had to get a supervisor involved to make the final decision of whether it was Form A or Form B. I suspect that this situation is very rare - espeically since we were still in posession of the original passport. Once the supervisor had agreed and the documents were accepted, I figured we were safe and I could relax. We paid for expedited shipping and left. (I don’t remember the reason, but we were not eligible to walk out of there with the passport in hand. Probably because it was form B vs Form A lol.) I think we were there less than an hour total, even with having to go from window to window.
I’m glad we didn’t use an expeditor because of the uncertainty between whether it was A or B and I felt like this was a one shot deal with regards to timing.
My advice is to make sure you have dotted every “i” and crossed every “t” and then check it all over again and bring more than you think you’ll ever need with you if you have to go out of town to make this happen.